Mycology Flashcards
Cell wall component of fungi
Chitin
Major membrane sterol in fungi
Ergosterol
Antifungal that inhibits ergosterol synthesis
Imidazoles (ketoconazole, miconazole, clotrimazole)
Antifungals that bind tightly to ergosterol and create pores
Polyenes (amphotericin B)
Live on dead organic material
Saprophytic or saprobic fungi
Lives on another living organism
Parasitic fungi
Single cells; replicate by budding
Yeast
Have hyphae (septate or nonseptate) and mycelia; replicate by mitosis
Molds
Property that allow fungi to grow as yeasts in tissues and molds at room temperature
Thermal dimorphism
Amanita mushroom toxins (2)
- Amantin, 2. Phylloidin
Produces aflatoxin, causing liver CA
Aspergillus flavus
Laboratory diagnoses of fungi (2)
- KOH, 2. Saboraud’s agar
Antifungal that inhibits glucan synthesis (component of cell wall)
Echinocandins (caspofungin, micafungin, and anidulafungin)
Inhibits conversion of squalene to lanosterol in ergosterol synthesis
Terbinafine, naftifine, amorolfine
Inhibits mitosis by affecting microtubule function
Griseofulvin
Affects fungal DNA synthesis
Flucytosine
Dermatophytes (3)
- Microsporum canis
- Trichophyton tonsurans
- Epidermophyton floccosum
Hypersensitivity reaction that occurs a distance away from the original site
Dermatophytid reaction
Athlete’s foot
Tinea pedis
Jock itch
Tina cruris
Dermatophytosis commonly seen in children
Tinea capitis
Facial hair dermatophytosis
Tinea barba
Tinea versicolor; spaghetti and meatballs morphology
Malassezia furfur
Dimorphic fungus that commonly affects rose gardeners
Sporothrix schenckii
Arthrospores (mold form) form spherules (yeast form), causing granulomata in the bones and CNS, erythema nodosum (“desert bumps”); also known as Valley fever
Coccidioides immitis
Antifungal that crosses the blood brain barrier; used in cases of fungal meningitis
Fluconazole
Dimorphic fungus; from bird droppings and bat guano; inhalation of microconidia causes TB-like illness; budding yeasts are found inside macrophages
Histoplasma capsulatum
Round yeast with broad based bud; most common cause of fungal pneumonia
Blastomyces dermatitidis
Thick yeast with multiple buds in wheel configuration (mariner’s wheel); causes chronic pneumonia with painful ulcers in men only
Paracoccidioides brasiliensis
Estrogen inhibits its growth
AKA Lutz-Splendore de Almeida disease or “man-hater fungus”
Oval yeast with a single bud or pseudohyphae
Candida albicans
Oral thrush, vulvovaginitis with curd-like discharge, intertrigo, satellite lesions on skin, onychomycosis
Candida infection in the immunocompetent
Pseudomembranous esophagitis, endocarditis, subcutaneous nodules
Candida infection in the immunocompromised
Oval yeast with narrow based bud that grows in bird (pigeon) droppings; can cause asymptomatic lung infection, meningitis, or encephalitis
Cryptococcus neoformans
Technique/dye used to visualize cryptococcus neoformans
India ink (nigrosin)
Exist only as molds with septate hyphae that form acute angles (V shaped configuration)
Aspergillus fumigatus
Can form fungus balls in lung cavities; causes asthma-like allgeric bronchopulmonary illness with expectoration of brownish bronchial plugs
Aspergillus fumigatus
Saprophytic molds with nonseptate hyphae that form right angles
Rhizopus oryzae and Mucor spp
Rhino-orbital-cerebral infection with eschar formation in patients with DKA, burns or leukemia
Mucormycosis (Rhizopus oryzae and Mucor spp)
Most common AIDS-defining illness (at CD4
Pneumocystis jiroveci pneumonia
Indeterminate organism with a surface glycoprotein undergoes programmed rearrangements; induces an inflammatory response producing a frothy exudate that causes VQ mismatch in the lungs
Pneumocystis jiroveci
DOC for PCP
TMP-SMX
